Commit 5456262d authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Jakub Kicinski
Browse files

net: Fix incorrect address comparison when searching for a bind2 bucket 



The v6_rcv_saddr and rcv_saddr are inside a union in the
'struct inet_bind2_bucket'.  When searching a bucket by following the
bhash2 hashtable chain, eg. inet_bind2_bucket_match, it is only using
the sk->sk_family and there is no way to check if the inet_bind2_bucket
has a v6 or v4 address in the union.  This leads to an uninit-value
KMSAN report in [0] and also potentially incorrect matches.

This patch fixes it by adding a family member to the inet_bind2_bucket
and then tests 'sk->sk_family != tb->family' before matching
the sk's address to the tb's address.

Cc: Joanne Koong <joannelkoong@gmail.com>
Fixes: 28044fc1 ("net: Add a bhash2 table hashed by port and address")
Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Tested-by: default avatarAlexander Potapenko <glider@google.com>
Link: https://lore.kernel.org/r/20220927002544.3381205-1-kafai@fb.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 30b172ee

include/net/inet_hashtables.h

+3 −0
Original line number Diff line number Diff line
@@ -95,6 +95,9 @@ struct inet_bind2_bucket { 
	possible_net_t		ib_net;

	int			l3mdev;

	unsigned short		port;

#if IS_ENABLED(CONFIG_IPV6)

	unsigned short		family;

#endif

	union {

#if IS_ENABLED(CONFIG_IPV6)

		struct in6_addr		v6_rcv_saddr;

net/ipv4/inet_hashtables.c

+10 −0
Original line number Diff line number Diff line
@@ -109,6 +109,7 @@ static void inet_bind2_bucket_init(struct inet_bind2_bucket *tb, 
	tb->l3mdev    = l3mdev;

	tb->port      = port;

#if IS_ENABLED(CONFIG_IPV6)

	tb->family    = sk->sk_family;

	if (sk->sk_family == AF_INET6)

		tb->v6_rcv_saddr = sk->sk_v6_rcv_saddr;

	else
@@ -146,6 +147,9 @@ static bool inet_bind2_bucket_addr_match(const struct inet_bind2_bucket *tb2, 
					 const struct sock *sk)

{

#if IS_ENABLED(CONFIG_IPV6)

	if (sk->sk_family != tb2->family)

		return false;



	if (sk->sk_family == AF_INET6)

		return ipv6_addr_equal(&tb2->v6_rcv_saddr,

				       &sk->sk_v6_rcv_saddr);
@@ -791,6 +795,9 @@ static bool inet_bind2_bucket_match(const struct inet_bind2_bucket *tb, 
				    int l3mdev, const struct sock *sk)

{

#if IS_ENABLED(CONFIG_IPV6)

	if (sk->sk_family != tb->family)

		return false;



	if (sk->sk_family == AF_INET6)

		return net_eq(ib2_net(tb), net) && tb->port == port &&

			tb->l3mdev == l3mdev &&
@@ -807,6 +814,9 @@ bool inet_bind2_bucket_match_addr_any(const struct inet_bind2_bucket *tb, const 
#if IS_ENABLED(CONFIG_IPV6)

	struct in6_addr addr_any = {};



	if (sk->sk_family != tb->family)

		return false;



	if (sk->sk_family == AF_INET6)

		return net_eq(ib2_net(tb), net) && tb->port == port &&

			tb->l3mdev == l3mdev &&